The invention relates to a stair-climbing chair system having improved safety.
FIG. 7 shows a conventional stair-climbing chair system which comprises a guide rail 3 provided along stairs 2, and a chair 4 which can be moved along the guide rail 3 by depressing a switch 5 on the chair 4.
For the safety of users, this system employs what is known as a dead-man arrangement in which the chair is activated only while the switch 5 is depressed by the user. Thus, a user has to keep pressing the switch 5 until he or she reaches his or her destination. In an emergency, the user can instantly stop the chair simply by releasing the finger from the switch 5.
This system is further provided with emergency stop switches 6 on the chair and at the boarding areas. When either of the switches 6 is pressed, a brake mounted on the chair 4 stops the chair instantly.
But this safety measure is not perfect for the following reasons.
(1) No provision is made for preventing the chair from moving suddenly if a user presses the switch unintentionally when sitting on or standing up from the
(2) No nighttime lighting is provided for illuminating the walkway of users. For particularly elderly users, this can cause an accident. The light may be kept on for this purpose. But keeping the light always turned on is a waste of energy.
(3) If an overweight user is on the chair, it may descend at an excessive speed due to gravity, shaking off the restriction by an emergency stop mechanism, and collide against the floor.
According to the present invention, there is provided a stair-climbing chair system comprising a guide rail laid along stairs, a chair slidably mounted on the rail, and a lifter for moving the chair along the rail. The chair is provided with a switch for activating the lifter, and a sensor is provided on the chair for detecting that a person is sitting on the chair and keeping the switch operative only while a person is sitting on the chair.
With this arrangement, the switch will not be turned on unless the user sits on the chair.
According to this invention, a lamp is provided which has a sensor adapted to turn the lamp on only while a person is near the lamp, and provided at a boarding station or at a predetermined location along the rail.
With this arrangement, the lamp will be automatically turned on to illuminate the walkway of the user, Thus the user can get on and off the chair safely.
With this arrangement, if the user is overweight so that the chair descends at an overspeed, the controller will stop the motor and activate the brake. If the free-fall preventive means should fail, the speed sensor will detect the overspeed and activate the brake. This ensures safety of the user.